mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-11-01 17:08:10 +00:00
171 lines
3.9 KiB
C
171 lines
3.9 KiB
C
/*
|
|
File: linux/posix_acl.h
|
|
|
|
(C) 2002 Andreas Gruenbacher, <a.gruenbacher@computer.org>
|
|
*/
|
|
|
|
|
|
#ifndef __LINUX_POSIX_ACL_H
|
|
#define __LINUX_POSIX_ACL_H
|
|
|
|
#include <linux/slab.h>
|
|
#include <linux/rcupdate.h>
|
|
|
|
#define ACL_UNDEFINED_ID (-1)
|
|
|
|
/* a_type field in acl_user_posix_entry_t */
|
|
#define ACL_TYPE_ACCESS (0x8000)
|
|
#define ACL_TYPE_DEFAULT (0x4000)
|
|
|
|
/* e_tag entry in struct posix_acl_entry */
|
|
#define ACL_USER_OBJ (0x01)
|
|
#define ACL_USER (0x02)
|
|
#define ACL_GROUP_OBJ (0x04)
|
|
#define ACL_GROUP (0x08)
|
|
#define ACL_MASK (0x10)
|
|
#define ACL_OTHER (0x20)
|
|
|
|
/* permissions in the e_perm field */
|
|
#define ACL_READ (0x04)
|
|
#define ACL_WRITE (0x02)
|
|
#define ACL_EXECUTE (0x01)
|
|
//#define ACL_ADD (0x08)
|
|
//#define ACL_DELETE (0x10)
|
|
|
|
struct posix_acl_entry {
|
|
short e_tag;
|
|
unsigned short e_perm;
|
|
unsigned int e_id;
|
|
};
|
|
|
|
struct posix_acl {
|
|
union {
|
|
atomic_t a_refcount;
|
|
struct rcu_head a_rcu;
|
|
};
|
|
unsigned int a_count;
|
|
struct posix_acl_entry a_entries[0];
|
|
};
|
|
|
|
#define FOREACH_ACL_ENTRY(pa, acl, pe) \
|
|
for(pa=(acl)->a_entries, pe=pa+(acl)->a_count; pa<pe; pa++)
|
|
|
|
|
|
/*
|
|
* Duplicate an ACL handle.
|
|
*/
|
|
static inline struct posix_acl *
|
|
posix_acl_dup(struct posix_acl *acl)
|
|
{
|
|
if (acl)
|
|
atomic_inc(&acl->a_refcount);
|
|
return acl;
|
|
}
|
|
|
|
/*
|
|
* Free an ACL handle.
|
|
*/
|
|
static inline void
|
|
posix_acl_release(struct posix_acl *acl)
|
|
{
|
|
if (acl && atomic_dec_and_test(&acl->a_refcount))
|
|
kfree_rcu(acl, a_rcu);
|
|
}
|
|
|
|
|
|
/* posix_acl.c */
|
|
|
|
extern void posix_acl_init(struct posix_acl *, int);
|
|
extern struct posix_acl *posix_acl_alloc(int, gfp_t);
|
|
extern int posix_acl_valid(const struct posix_acl *);
|
|
extern int posix_acl_permission(struct inode *, const struct posix_acl *, int);
|
|
extern struct posix_acl *posix_acl_from_mode(umode_t, gfp_t);
|
|
extern int posix_acl_equiv_mode(const struct posix_acl *, umode_t *);
|
|
extern int posix_acl_create(struct posix_acl **, gfp_t, umode_t *);
|
|
extern int posix_acl_chmod(struct posix_acl **, gfp_t, umode_t);
|
|
|
|
extern struct posix_acl *get_posix_acl(struct inode *, int);
|
|
extern int set_posix_acl(struct inode *, int, struct posix_acl *);
|
|
|
|
#ifdef CONFIG_FS_POSIX_ACL
|
|
static inline struct posix_acl **acl_by_type(struct inode *inode, int type)
|
|
{
|
|
switch (type) {
|
|
case ACL_TYPE_ACCESS:
|
|
return &inode->i_acl;
|
|
case ACL_TYPE_DEFAULT:
|
|
return &inode->i_default_acl;
|
|
default:
|
|
BUG();
|
|
}
|
|
}
|
|
|
|
static inline struct posix_acl *get_cached_acl(struct inode *inode, int type)
|
|
{
|
|
struct posix_acl **p = acl_by_type(inode, type);
|
|
struct posix_acl *acl = ACCESS_ONCE(*p);
|
|
if (acl) {
|
|
spin_lock(&inode->i_lock);
|
|
acl = *p;
|
|
if (acl != ACL_NOT_CACHED)
|
|
acl = posix_acl_dup(acl);
|
|
spin_unlock(&inode->i_lock);
|
|
}
|
|
return acl;
|
|
}
|
|
|
|
static inline struct posix_acl *get_cached_acl_rcu(struct inode *inode, int type)
|
|
{
|
|
return rcu_dereference(*acl_by_type(inode, type));
|
|
}
|
|
|
|
static inline void set_cached_acl(struct inode *inode,
|
|
int type,
|
|
struct posix_acl *acl)
|
|
{
|
|
struct posix_acl **p = acl_by_type(inode, type);
|
|
struct posix_acl *old;
|
|
spin_lock(&inode->i_lock);
|
|
old = *p;
|
|
rcu_assign_pointer(*p, posix_acl_dup(acl));
|
|
spin_unlock(&inode->i_lock);
|
|
if (old != ACL_NOT_CACHED)
|
|
posix_acl_release(old);
|
|
}
|
|
|
|
static inline void forget_cached_acl(struct inode *inode, int type)
|
|
{
|
|
struct posix_acl **p = acl_by_type(inode, type);
|
|
struct posix_acl *old;
|
|
spin_lock(&inode->i_lock);
|
|
old = *p;
|
|
*p = ACL_NOT_CACHED;
|
|
spin_unlock(&inode->i_lock);
|
|
if (old != ACL_NOT_CACHED)
|
|
posix_acl_release(old);
|
|
}
|
|
|
|
static inline void forget_all_cached_acls(struct inode *inode)
|
|
{
|
|
struct posix_acl *old_access, *old_default;
|
|
spin_lock(&inode->i_lock);
|
|
old_access = inode->i_acl;
|
|
old_default = inode->i_default_acl;
|
|
inode->i_acl = inode->i_default_acl = ACL_NOT_CACHED;
|
|
spin_unlock(&inode->i_lock);
|
|
if (old_access != ACL_NOT_CACHED)
|
|
posix_acl_release(old_access);
|
|
if (old_default != ACL_NOT_CACHED)
|
|
posix_acl_release(old_default);
|
|
}
|
|
#endif
|
|
|
|
static inline void cache_no_acl(struct inode *inode)
|
|
{
|
|
#ifdef CONFIG_FS_POSIX_ACL
|
|
inode->i_acl = NULL;
|
|
inode->i_default_acl = NULL;
|
|
#endif
|
|
}
|
|
|
|
#endif /* __LINUX_POSIX_ACL_H */
|